Analog Devices LTC2485 Product Info

• Easy Drive^™ Technology Enables Rail-to-Rail Inputs with Zero Differential Input Current
• Directly Digitizes High Impedance Sensors with Full Accuracy
• GND to V_CC Input/Reference Common Mode Range
• 2-Wire I²C Interface
• Programmable 50Hz, 60Hz or Simultaneous 50Hz/60Hz Rejection Mode
• 2ppm (0.25LSB) INL, No Missing Codes
• 1ppm Offset and 15ppm Full-Scale Error
• Selectable 2x Speed Mode
• No Latency: Digital Filter Settles in a Single Cycle
• Single Supply 2.7V to 5.5V Operation
• Internal Oscillator
• Six Addresses Available and One Global Address for Synchronization
• Available in a Tiny (3mm × 3mm) 10-Lead DFN Package

The LTC2485 combines a 24-bit plus sign No Latency ΔΣ^™ analog-to-digital converter with patented Easy Drive technology and I²C digital interface. The patented sampling scheme eliminates dynamic input current errors and the shortcomings of on-chip buffering through automatic cancellation of differential input current. This allows large external source impedances and input signals, with rail-to-rail input range to be directly digitized while maintaining exceptional DC accuracy.

The LTC2485 includes an on-chip oscillator. The LTC2485 can be configured through an I²C interface to reject line frequencies. 50Hz, 60Hz or simultaneous 50Hz/60Hz line frequency rejection can be selected as well as a 2x speed-up mode.

The LTC2485 allows a wide common mode input range (0V to V_CC) independent of the reference voltage. The reference can be as low as 100mV or can be tied directly to V_CC. The LTC2485 includes an on-chip trimmed oscillator eliminating the need for external crystals or oscillators. Absolute accuracy and low drift are automatically maintained through continuous, transparent, offset and full-scale calibration.

Applications

• Direct Sensor Digitizer
• Weight Scales
• Direct Temperature Measurement
• Strain Gauge Transducers
• Instrumentation
• Industrial Process Control
• DVMs and Meters